Q: We treat our 10-year-old male boxer dog routinely for fleas. However a recent exposure to fleas seems to be unresponsive to treatment. We also have cat who we suspect is never with fleas as she constantly grooms. We wondered if there was any other treatment, shampoo, spray, spot on or medication we could give in addition to monthly frontline to prevent environmental reinfestation?

Lou Johnson, North Tyneside

A: The majority of fleas found on dogs are the cat flea and 95% of them live in the environment rather than on the dog. If there is a cat in the environment, it is likely the cat is affected too. All dogs, cats and rabbits in the environment should be treated regularly to minimise the environmental burden.

I would not recommend any shampoos to get rid of fleas. Flea shampoos might have some activity against the fleas on the dog while the shampoo is in contact with the skin but once rinsed off, the fleas in the environment can simply jump back onto the dog and restart the cycle. Shampoos can also reduce the efficacy of spot-on treatments such as frontline.

Fipronil (the drug in frontline), at the correct dose, is one of the best flea treatments you can get without a prescription. If you are unhappy with its efficacy, there are a variety of prescription flea treatments (both tablet and spot-on) that are likely to be more effective as they have a much faster onset of action and will kill more stages of the flea life cycle than frontline. Some also prevent environmental reinfestation.

Every veterinary practice has their own preference as to which prescription product they stock and they all have advantages and disadvantages so you are best to discuss your options with your veterinary nurse.

Please note that advice in this section is for general guidance, and if your pet is very unwell you should contact your veterinary surgeon as soon as possible as this advice does not replace the need for a clinical examination of your pet.